The present invention relates to a revolving cutting press, and more particularly to such a revolving cutting press which has at least one rotatable revolving plate, with a plurality of tool receptacles for tool sets in its peripheral region, and a working station arranged so that any of the tool sets can be transferred to the working station during rotation of the revolving plate and coupled with a plunger.
Revolving cutting presses of the above-mentioned general type are known in the art. They are used as machines for working plate-shaped workpieces in numerous forms. Generally they have two revolving plates which are arranged over one another and provided in their peripheral region with complete tool sets. The tool set can be formed of an upper tool which includes at least a punch holder with a punch, and a lower tool which includes a matrix. In addition, a stripper is provided for facilitating a withdrawal of the punch from the workpiece after punching or cutting process.
The substantial advantage of these revolving cutting presses is that it is possible to provide a very fast exchange of the tool set which is located in the working station, by pure rotation of the revolving plate. On the other hand, the tool capacity of the known revolving cutting presses is practically limited by the structural size of the revolving plates. Also, in the sense of the achievable tool exchange with this progressive increase of the radii of the revolving plates, respective power increase of their rotary drives is required since the increase in radii leads to overproportionally increased inertia moments.
U.S. Pat. No. 3,685,380 discloses a revolving cutting press with the revolving plates which support the tool sets arranged along several circles which are concentric to the axis of the plate. In correspondence with the number of the circles, an increase of the tool reservoir is achieved. However, the tool sets which are arranged especially on the inner circle are accessible with difficulties so that their exchange is considerably complicated. A further disadvantage of this construction is that during a transfer of the tool sets from one to the other circle a respective subsequent movement of the tool is required.
The German document DE-OS No. 3,241,046 shows special constructions of punching tools, in which those parts of punch are engaged with the workpiece which are selected by actuation of a cam disc. The disadvantage of this approach is that no standard punch tools can be used and a stripper which narrowly surrounds the punch must be dispensed with. Finally, this embodiment possesses the same above-described disadvantage in that depending on the respective punch part for engagement, the coordinate position of the workpiece must be constantly changed. This increases the dead time which occurs during working of a workpiece. Finally, the application of the above-mentioned tool is limited to relatively thin sheets.